CHARACTERISING THE AMENABILITY OF GOLD ORE FOR GRAVITY PRE-CONCENTRATION USING LST FLUIDIZATION IN THE REFLUX CLASSIFIER

摘要

The energy required for comminution increases significantly with decreasing nominal grind size, particularly below 100 urn where the majority of the value is liberated in typical gold mining operations. For increasingly lower grade ores, it has become widely recognised that pre-concentration prior to the milling circuit is a potential strategy for managing the rising dominance of the gangue. High recovery, upgrade and mass rejection are necessary to justify implementation, so one of the main challenges is assessing feed specific amenability to various separation processes. For gravity separation, the sink/float test has traditionally provided the necessary information, though the technique is undesirable due to high costs and safety issues associated with the toxic heavy liquids. This paper describes an alternative technique for assessing gravity pre-concentration amenability based on hydrodynamic fractionation in a semi-batch REFLUX Classifier. Recent work has established excellent agreement with the sink/float test for dense minerals using an aqueous solution of lithium heteropolytunsgates (LST) as the fluidizing liquid. Here, the technique is extended to develop a methodology for quantifying gravity separation potential. A case study is presented on an Australian porphyry copper-gold ore which analyses the potential for gravity pre-concentration and models separation performance by applying the partition surface.